A common first target is one month of essential costs: rent, food, transport and bills. Once you reach it, many people work towards three to six months. Keep it in an easy-to-reach savings account, separate from spending money, so it is there when something unexpected happens.
General tips from the Cashflow Team, not financial, tax or legal advice. Your situation is different, so talk to a qualified professional before big decisions.
Track it in Cashflow
Cashflow: Budget Manager is a free app to scan receipts, set budgets and savings goals, and see where your money goes.